1. Field of the Invention
The present invention generally relates to a mobile communications system, and in particular to a method and system for identifying a mobile communication station.
2. Description of the Related Art
In mobile communications, a mobile telephone user may move between different networks. Therefore, it is very important to support services without interruption in multiple networks. Such a capability is known as roaming. To realize the roaming, an identifier such as a subscriber number which identifies the mobile terminal is needed in each network to exchange the location and other necessary information of a mobile terminal between networks.
A roaming technique using a temporary number as an identifier has been disclosed in Japanese Patent Unexamined Publication No. 5-14271. In this roaming technique, when moving from a home network to an adjacent different network, a mobile terminal transmits its subscriber number and a roaming request to the visiting network and thereby the visiting network assigns a roaming umber as a temporary identifier to the mobile terminal. While the mobile terminal is located in the visiting network, the roaming number is used to provide services. When back to the home network, the mobile terminal uses the subscriber number to perform radio communications.